We have been re-writing copypool volumes (several pools) this year onto fresh
3590 media. The age of the media has varied between 6 months and 2.5 years.
One pool of almost 800 tapes (the site-wide backup pool) has so far yielded 10
that were unreadable or partially unreadable. Other smaller pools (100 tapes)
had no unreadable tapes.
For speed of processing and to minimise tape mounts we opted to check the
copypool tapes back in in batches and use move data from the now onsite
volumes. The other benefit was that we were able to identify doubtful media.
I have found this somewhat disappointing in that one is led to believe that
3590 media and decks are of very high quality. But, given the history of our
3590 tape drives and microcode over (almost) the last three years, it is in
some ways a pleasant surprise that there were not more failures.
We have always used "private" and not "scratch" tapes in pools, one reason
being that the media history is more trackable. I always replace tapes that
have "write" errors and repeatable "read" errors. It is my understanding that
3590 media is guaranteed for 10 years.
Hope this is of interest ...
Regards, Sheelagh
------------------------------------------------------------------------------
-----
Sheelagh Treweek Email: Sheelagh Treweek
Email: sheelagh.treweek AT oucs.ox.ac DOT uk
Oxford University Computing Services Tel: +44 (0)1865 273205
13 Banbury Road, Oxford, OX2 6NN, UK Fax: +44 (0)1865 273275
------------------------------------------------------------------------------
-----
> From owner-adsm-l AT vm.marist DOT edu Wed Aug 26 16:35:45 1998
> From owner-adsm-l AT vm.marist DOT edu Wed Aug 26 16:35:45 1998
> MIME-Version: 1.0
> Content-Transfer-Encoding: quoted-printable
> Date: Wed, 26 Aug 1998 10:16:20 -0500
> From: Hilton Tina <HiltonT AT TCE DOT COM>
> Subject: Re: read tests
> To: ADSM-L AT VM.MARIST DOT EDU
>
> Normal reclamation seems to take care of this at our shop. However, I am
> thinking about writing a script that will query the last read/write date and
> issue a 'move data' on those that are old. I'd probably do it before 5
> years, although I haven't decided for sure yet.
>
> Tina
>
> > -----Original Message-----
> > From: Roger Hohmann [SMTP:roger_hohmann AT WESTLB DOT DE]
> > Sent: Wednesday, August 26, 1998 8:51 AM
> > To: ADSM-L AT VM.MARIST DOT EDU
> > Subject: read tests
> >
> > I was asked how I would recognize tapes which will become unreadable
> > because of their age. I don't expect this problem in the nearer future,
> > but
> > - what if I save a group of files today, make a backup storagepool
> > tomorrow
> > and the file is never changed or deleted and the affected tapes are never
> > used. One day in the far future, I want to restore this file, and - tape
> > and copy tape are defect because of their age (loss of magnetic fields or
> > so).
> >
> > Does anyone do any 'read checks' of elder tapes or do I have to make a
> > 'move data' of all tapes which are elder than 5 years?
> >
> > Regards
> >
> >
> > Roger Hohmann
> >
> > WestLB
> > Division: 009 Services
> > Abteilung: 001-80633
> > Herzogstraße 15
> > D - 40217 Düsseldorf
> > Tel.: +49211 826 8155
> > mailto:roger_hohmann AT westlb DOT de
|
